Răspuns :
(11 * 10 + 21 - 77 : 7) + a = 1048
(110 + 21 - 11) + a = 1048
120 + a = 1048
a = 1048 - 120
a = 928
(110 + 21 - 11) + a = 1048
120 + a = 1048
a = 1048 - 120
a = 928